Image recording apparatus for recording an image on a recording medium

ABSTRACT

An image recording apparatus records an image on a recording medium by causing a recording head having an arrangement of a plurality of recording elements to conduct its main scanning for the recording medium interrelatedly in the direction opposite to the arrangement of the recording elements. The apparatus comprises a setting device to set the number of main scannings by the recording head; a main scanning device to perform recording by plural numbers of main scannings with respect to one pixel by causing the recording head to conduct its main scannings for the same recording area of the recording medium in accordance with the number set by the setting device; and a sub-scanning device to cause the recording head and the recording medium to be sub-scanned interrelatedly per main scanning in an amount smaller than the width of the arrangement of the recording elements of the recording head. Hence, even if a disabled ejection occurs in one scanning at the time of recording by a multi-scanning, the missing dot is complemented by the following scan to make it possible to obtain an image having no image defects at all times.

CROSS REFERENCE TO RELATED APPLICATIONS

This is a divisional application of Application No. 09/489,910 filedJan. 24, 2000 now U.S. Pat. No. 6,547,361, which is a divisionalapplication of application No. 08/021,102 filed Feb. 23, 1993, now U.S.Pat. No. 6,036,300, issued Mar. 14, 2000.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a method for recording image and anapparatus therefor, and a medium recorded by such an apparatus. Moreparticularly, the invention relates to an image recording method torecord an image on a recording medium by enabling a recording head toscan, and an apparatus therefor, and a medium recorded by such anapparatus.

2. Related Background Art

There is well known an image recording apparatus of the so-called serialscanning type wherein a recording head provided with a plurality ofrecording elements (exothermic resistive members, nozzles, and the like)is caused to scan for recording. FIG. 2 is a view illustrating arecording method of such a serial scanning type as this, in which areference numeral 201 designates an ink jet head with an arrangement ofplural nozzles 202. An image recording is performed per recording widthd corresponding to the arrangement of the nozzles 202 of this ink jethead 201 while the ink jet head 201 is being scanned on a recordingsheet 203 in the direction A. Thus, when a recording of the recordingwidth d is terminated, the recording sheet 203 is shifted in thedirection B for a length corresponding to the recording width d. Then,the ink jet head 201 is again caused to scan in the direction A toperform another image recording for the recording width d. The recordingby such a serial scanning method as this has an advantage that an imagedata having a large image surface can be recorded by a small head. Onthe other hand, there is a disadvantage that should there be any nozzlesthat may be disabled to eject ink or may cause the positions of recordeddots to be displaced among the nozzles of the head 201, such a portionappears continuously in the direction A, which tends to createcontinuous white streaks. In order to compensate for a disadvantage ofthe kind, there is proposed a recording method by multi-scanning whichwill be described later.

FIG. 3A is a view illustrating such a multi-scanning as this.

An ink jet head 301 has twelve nozzles as designated by referencenumerals 1-1 to 1-12. These nozzles can be divided into two portionsindicated by reference marks X and Y. Here, the nozzles corresponding tothe X portion are represented by 1-1 to 1-6 while the nozzlescorresponding to the Y portion are represented by 1-7 to 1-12. At first,a recording by the X portion of the ink jet head 301 is performed withthe initial scanning for recording on the portion of a recording sheet203 at X′ (the recorded dots by this recording are represented by X1 toX6). Then, in continuation, the recording sheet 203 is shifted in thedirection B in the sub-scanning direction by an amount d in order torecord dots Y1 to Y6 (represented by Y′) using the Y portion of the head301. By recording in this way, the dots recorded by the use of the samenozzles are not continuous in the direction A. Therefore, even if thereare nozzles causing the positions of the recording dots to be displaced,the dots thus recorded do not appear continuously in the direction A;hence resulting in an advantage that the white streaks in the directionA are not remarkably noticeable.

Also, the recording density unevenness due to the irregularity of inkejection amounts per nozzle is offset by the recording thus performed,and such unevenness is not remarkably noticeable, either. Also, if therecording duty of the ink jet head is high, the ink mist is accumulatedin the vicinity of the orifice to hinder the ink ejection in some cases,but when the multi-scanning is performed, dots are thinned out to enablethe number of ink ejections per unit period of time to be reduced; hencesuppressing the generation of the mist. An advantage is brought aboutthat the disabled ejection due to mist is reduced.

Nevertheless, there are still the images for which the ink ejectiondefects causing the white streaks, density unevenness, and mist cannotbe prevented only by the foregoing two-time multi-scanning. For example,if a uniform pattern should be recorded, the white streaks and densityunevenness become extremely conspicuous, and in some cases, not only theforegoing two-time multi-scanning, three- or four-time multi-scanning isalso required.

Also, for an image requiring a high recording duty, it is insufficientto make the recording duty a half by the two-time multi-scanning. Thereare some cases where it is better to reduce the recording duty to a ⅓or¼by the three- or four-time multi-scanning.

On the other hand, however, there is a problem that if the number ofmulti-scannings is increased, the recording period of time is prolongedthat much.

FIG. 3B is a view illustrating another example of such a multi-scanningas this.

The nozzles 302 of the ink jet head 301 can be divided into threeportions designated by reference marks X, Y, and Z. The portions includethe nozzles X-1 to X-4, Y-1 to Y-4, and Z-1 to Z-4, respectively. Atfirst, with the initial scanning, a recording is performed by theportion X of the ink jet head 301 for the portion of the recording sheet203 at X′ (the dots formed by this recording are represented by X-1 toX-4). Then, the recording sheet 203 is shifted in the direction B by din the sub-scanning direction, and dots Y-1 to Y-4 (represented by Y′)are recorded using the portion Y of the head 301. However, at thisjuncture, the portion X of the ink jet head 301 performs its recordingin a position at X. Then, continuously, the recording sheet 203 is againshifted in the direction B by d for recording by the use of the portionZ of the ink jet head 301. At this juncture, as shown in FIG. 3B, therecording is performed in such a manner that the dots recorded by theuse of the same nozzle are not continuous in the direction A. Therefore,even if there are the nozzles causing the displacement of the recordingdots, the dots thus recorded do not appear continuously in the directionA. The advantage is that the white streaks in the direction A are notremarkably noticeable.

However, if there are any nozzles performing incomplete ejection, aproblem is still encountered that the white streaks remain as clearimage defects, although the white streaks are less conspicuous by themulti-scanning than by the usual serial scanning. Particularly when therecording duty is high, the ink mist is apt to be generated. This typeof ink mist is accumulated on the head surface to cover the nozzles;thus disabling the ink ejection in some cases. A disabled ink ejectionof the kind is different from the genuine nozzle clogging or the like,and is dependent on the degree of the density of an image. As a result,it occurs at random in an image or it is often recovered itself; thusmaking its countermeasure difficult.

Also, in FIG. 3B, when the head is scanned in the direction A to recordan image, the head temperature is increased due to the accumulation ofthe ejection driving energy. Thus, the viscosity of ink is lowered andthe ejecting amount of ink is also increased. As a result, the imagedensity is in general higher toward the termination of recording than atthe time of initiating the recording at each scan. This phenomenongenerally presents a problem in any image, but particularly when outputimages are joined together to form one image, that is, when theso-called enlarged continuous copying mode is used, the difference indensities will become more conspicuous. If a multi-scanning isperformed, the number of ink droplets ejected per unit time per nozzleis reduced as is clear from FIG. 3B. In the case represented in FIG. 3B,it is reduced to a ⅓ approximately. Therefore, the head temperature riseis suppressed as compared to the case of using the usual serialscanning. However, the above-mentioned problem still remains unsolved.Also, the seriousness of this problem differs depending on the imagepattern to be recorded. In other words, when a pattern having a largeimage ratio is recorded, this becomes a serious problem, but when apattern having a small image ratio is recorded, it is not so serious aproblem.

SUMMARY OF THE INVENTION

The present invention is designed in consideration of the problemsrelated to the prior art as described above with attention given to anew aspect which has never been predicted.

It is a first object of the present invention to provide a method forrecording image capable of obtaining a recorded image of a high imagequality without lowering its recording speed unnecessarily by settingthe number of multi-scannings in accordance with the image data to berecorded, and an apparatus therefor, and a medium recorded by such anapparatus.

Also, it is another object of the first invention to provide an imagerecording apparatus, in which a recording head having the arrangement ofplural recording elements is caused to perform its main scanningrelatively with respect to a recording medium in the direction differentfrom the foregoing arrangement to record the image on the recordingmedium, comprising the following:

setting means to set up a number of the main scannings by the aforesaidrecording head;

main scanning means to cause the aforesaid recording head to perform itsmain scannings for a same recording area in accordance with the mainscanning number set up by the aforesaid setting means in order toperform recording by the number of plural main scannings per pixel; and

sub-scanning means to cause the aforesaid recording head and theaforesaid recording medium to be relatively sub-scanned per theaforesaid main scanning for an amount smaller than the width of the areawhere the recording elements of the recording head are arranged.

Also, it is a second object of the present invention to provide a methodfor recording image capable of obtaining a recorded image having a highimage quality without any image defects, and an apparatus therefor, anda medium recorded by such an apparatus.

Further, it is another object of the second invention to provide animage recording apparatus to record image on a recording medium bycausing a recording head having a plurality of recording elements torelatively scan the recording medium, comprising the following:

recording means to perform recording by causing the aforesaid recordinghead to relatively scan the recording area of the aforesaid recordingmedium for plural numbers;

reading means to read a recorded image which is recorded on theaforesaid recording medium by relatively scanning the recording area ofthe aforesaid recording medium together with the aforesaid recordinghead at the time of the execution of recording by the aforesaidrecording means;

determining means to determine an area having a defective recording bycomparing the recorded image read by the aforesaid reading means withthe information of the image to be recorded essentially; and

complementary recording means to perform a complementary recording inthe subsequent scanning by the aforesaid recording head for the areahaving the defective recording determined by the aforesaid determiningmeans.

Also, it is other objects of the present invention to provide a methodfor recording image on a recording medium using these image recordingapparatuses, and a medium recorded as a result thereof.

It should be noted that the term “recording” used in the presentspecification and claims includes a meaning of “printing” and signifiesin a broad sense providing an image on a recording medium such as clothsmade of cotton or silk, etc. and paper. It should be also noted that thelanguage “recording” does not limit the scope of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a block diagram schematically showing the structure of theprincipal part of a printing apparatus according to a first embodimentof the first invention.

FIG. 2 is a view illustrating a recording state of a conventionalrecording head of a serial recording type.

FIGS. 3A and 3B are views illustrating multi-scanning recording methods.

FIG. 4 is a flowchart showing the control process in a printingapparatus according to the first embodiment of the first invention.

FIG. 5 is a flowchart showing the process according to a secondembodiment of the first invention.

FIG. 6 is a block diagram schematically illustrating the structure of animage determining unit according to a third embodiment of the firstinvention.

FIG. 7 is a view illustrating a multi-scanning according to anotherembodiment of the first invention.

FIG. 8 is a block diagram showing a structural example of the system ofa recording apparatus according to the present invention.

FIG. 9 is a view schematically showing a mode of a recording apparatusprovided with a two-staged head preferably suitable for the presentinvention.

FIG. 10 is a partially cut off perspective view showing a structuralexample of the principal part of an ink jet recording apparatusaccording to the present invention.

FIG. 11 is an enlarged perspective view showing the structure of thevincinity of the head unit of the recording apparatus shown in FIG. 9.

FIG. 12 is a block diagram illustrating an embodiment of an ink jetrecording method.

FIG. 13 is a view illustrating the recording operation of a fourthembodiment of the second invention.

FIG. 14 is a block diagram schematically showing the structure of aprinting apparatus according to the fourth embodiment of the secondinvention.

FIG. 15 and FIG. 16 are flowcharts showing the recording process in theprinting apparatus according to the fourth embodiment of the secondinvention.

FIG. 17 is a view illustrating the recording operation of a fifthembodiment of the second invention.

FIG. 18 is a view illustrating the recording operation of a sixthembodiment of the second invention.

FIG. 19 is a block diagram schematically showing the structure of aprinting apparatus according to the sixth embodiment of the secondinvention.

FIG. 20 and FIG. 21 are flowcharts showing the recording process in aprinting apparatus according to the seventh embodiment of the secondinvention.

FIG. 22 is a view illustrating the recording operation of a printingapparatus according to an eighth embodiment of the second invention.

FIG. 23 is a block diagram showing the structure of the principal partof a printing apparatus according to a ninth embodiment of the secondinvention.

FIG. 24 is a view showing the γ correction characteristics in the γcontrol unit of a printing apparatus according to the ninth embodimentof the second invention.

FIG. 25 is a block diagram showing the structure of the principal partof a printing apparatus according to a tenth embodiment of the secondinvention.

FIG. 26 is a cross sectional view showing a recording apparatusaccording to an eleventh embodiment.

FIG. 27 is a perspective view illustrating the recording unit of arecording apparatus according to the eleventh embodiment.

FIG. 28 is a perspective view illustrating the monitor unit of anrecording apparatus according to the eleventh embodiment.

FIG. 29 is a cross sectional view showing the recording head and inksupply system shown in FIG. 27.

FIG. 30 is a block diagram schematically showing the structure of arecording apparatus according to the eleventh embodiment.

FIG. 31 is a view showing an example of the image defect due to thedefective ejection of a nozzle.

FIG. 32 is a flowchart showing the recording process in a printingapparatus according to the eleventh embodiment.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Hereinafter, with reference to the accompanying drawings, the detaileddescription will be made of the preferable embodiments according to thepresent invention.

FIG. 8 is a block diagram showing an example of the fundamentalstructure which is applied to an ink jet recording apparatus exemplifiedas an image recording apparatus according to the present invention. Thisink jet recording apparatus is structured as a system roughlycomprising:

an image reading device 1 to read an original image produced by adesigner and others and convert this original image into the originalimage data which represent the original image by electric signals;

an image processing unit 2 to receive the original image data from theimage reading device 1 for processing and output them as the image data;and

an image recording unit 3 to perform recording on cotton, silk, andother recording media in accordance with the image data produced by theimage processing unit 2. In the image reading device 1, the originalimage is read by a CCD image sensor. In the image processing unit 2, thedata are produced from the inputted original image data in order todrive the ink jet recording unit A-2 (FIG. 9) which ejects four colorink materials, magenta (abbreviated as M), cyanogen (abbreviated as C),yellow (abbreviated as Y), and black (abbreviated as Bk), which will bedescribed later. When the data are produced, there are performed animage processing for the reproduction of the original image with inkdots; the distribution of colors to determine the color tone; themodification of the layout; and the rearrangement of the sizes for andthe selection of the patterns by enlargement, contraction, or the like.In the image recording unit 3, recording is performed by the ink Jetrecording unit A-2. The ink jet recording unit A-2 causes fine inkdroplets to fly toward the recording medium for recording by theadhesion of these ink droplets to the recording medium.

FIG. 10 is a perspective view showing an example of an ink jet recordingapparatus to be used for the present invention.

At first, an ink jet recording unit 100 is structured by a frame 6, twoguide rails 7 and 8, an ink jet head 9 and a carriage 10 to carry thehead, an ink supply device 11 and a carriage 12 to carry it, and a headrecovery device 13 and an electric power supply system 5 according tothe broad classification of the constituents. The ink jet head 9(hereinafter simply referred to as head) includes a plurality of nozzlearrays and transducers to transduce electric signals into the inkejection energy, and has a mechanism to selectively eject ink from thenozzle arrays in accordance with the image signals transmitted from animage processing unit (not shown).

The foregoing head is a recording head which ejects ink by theutilization of thermal energy, and is provided with the thermal energytransducers which generate thermal energy given to ink. It is preferableto use a head wherein the ink is caused to change its state by thethermal energy given thereto by the foregoing thermal energy transducersto eject it from the discharging ports on the basis of the foregoingchange of state thus generated.

The ink supply device 11 stores ink and supplies it to the head asrequired, and has an ink tank, an ink pump, and the like which are notshown. The supply device 11 and the head 9 are connected by ink supplytubes 15, and usually, the ink is automatically supplied to the head 9by a capillary phenomenon by the amount to be ejected. Also, inoperating a head recovery which will be described later, the ink isforcibly supplied to the head 9 using the ink pump.

The above-mentioned head 9 and ink supply device 11 are respectivelymounted on a carriage 10 and a carriage 12, and are structured toreciprocate along the guide rails 7 and 8 by a driving device which isnot shown.

The head recovery device 13 is provided at a position opposite to thehead 9 in the home position (standby position) of the head 9 in order tomaintain the ink ejection stability of the head, and is able to advanceor retract in the direction indicted by an arrow A. More specifically,it will operate as given below.

At first, the capping of the head 9 (capping operation) is performed inthe home position in order to prevent ink in the nozzles of the head 9from being evaporated when the head is at rest, or to execute a functionto collect the exhausted ink when an operation (pressurized recoveryoperation) is performed to cause ink to be exhausted forcibly from thenozzles by giving pressure to the ink passage in the head by the use ofa pump in order to remove bubbles and dust particles in the nozzlesbefore starting an image recording, or an operation (suction recoveryoperation) is performed to suck and exhaust ink forcibly from thenozzles.

The electric power supply system 5 includes a control unit to controlthe overall sequence of the power unit and ink jet recording unit. Acloth 16 is fed for a given amount in the sub-scanning direction(direction indicated by an arrow B) by a feeding device which is notshown for each time a recording is performed for a given length with theshifting of the head 9 along the carriage 7 in the main scanningdirection. Thus, the image formation is carried out. In FIG. 10, theportion 17 indicated by slanted lines represents the portion where therecording has been made.

In this respect, it may be possible for the recording head 9 to use anink jet recording head for a monochrome recording, the plural recordingheads to perform recording in ink of different colors for a colorrecording, or plural recording heads to perform recording in a variabledensity ink of a same color among others.

Also, irrespective of the recording means and the structures of the inktank, it is possible to apply various types of heads such as a cartridgetype wherein a recording head and an ink tank are formed integrally, ora type which is structured by connecting the separately formed recordinghead and ink tank by the ink supply tubes.

Furthermore, it is possible to obtain images of a high quality on arecording medium having an extremely low water absorption byimplementing the present invention in a recording apparatus of a modeset forth below. FIG. 9 is a view schematically showing a recordingapparatus particularly preferable for a method of the present invention.This recording apparatus roughly comprises a cloth supply unit B to feeda rolled cotton cloth, silk, or other recording media which arepreliminarily processed for printing; a main unit A to precisely feedthe cloth thus carried line by line for printing by the ink jet head;and a winding unit C to dry and wind the printed cloth. The main unit Afurther comprises a precision feed unit A-1 for cloth including aplaten, and a printing unit A-2. FIG. 11 is a perspective view showingthe structure of the printing unit A-2 in detail.

Hereinafter, taking as an example a case of printing a preliminarilyprocessed cloth as a recording medium, the operation of this apparatuswill be described.

A rolled cloth 36 which is preliminarily processed is fed to the clothsupply unit and then to the main unit A. In the main unit, a thinendless belt 37 is tensioned around a driving roller 47 and a windingroller 49, which is step driven precisely. The driving roller 47 is stepdriven directly by a high resolution stepping motor (not shown) to stepfeed the belt by such a stepping amount thereof. The cloth 36 thus fedis pressed and tensioned by a pressing roller 40 to the surface of thebelt 37 which is backed up by the winding roller 49.

The cloth 36 thus step fed by the belt is positioned by the platen 32arranged behind the belt in the first printing unit 31; thus beingprinted by the ink jet head 9 from its surface side. Each time one lineof printing is terminated, the cloth is step fed for a predeterminedamount. Then, it is dried from its surface by the heated draft producedby a hot plate 34 from the behind the belt and supplied or exhaustedthrough a hot air duct 35. Subsequently, superposed printing isperformed in the second printing unit 31′ in the same method as in thefirst printing unit. The cloth printed completely is drawn apart andguided to a post drying unit 46 comprising the hot plate and hot airduct as in the foregoing drying unit where it is again dried; thus beingguided by a guide roller 41 to the winding roller 48 for winding. Thewound cloth is removed from the apparatus and processed as a finishedproduct through a batch processing of coloring, cleaning, drying, andthe like.

In accordance with FIG. 11, the details of the printing unit A-2 will bedescribed.

A preferable mode here is such that by the head in the first recordingunit, the information is recorded while thinning the dot numbers, andthen, after the drying process, the ink droplets are ejected by the headin the second printing unit to complement the information which has beenthinned in the first printing unit.

In FIG. 11, the cloth 36 which is a recording medium is mounted on thebelt 37 under tension and is being step fed in the upper direction inFIG. 11. For the first printing unit 31 located in the lower part ofFIG. 11, a first carriage 44 is provided with a mounted ink jet head forY, M, C, Bk, and special colors S1 to S4. The ink jet head (recordinghead) used for this embodiment is a head having the elements whichgenerate the thermal energy to give the film boiling utilized as energyto ink to cause it to be ejected, and in such a head, 128 dischargingports are arranged with a density of 400 DPI (dot/inch).

On the downstream side of the first printing unit, there are arranged ahot plate 34 to apply heat from the back side of the belt, and a dryingunit 45 comprising a hot air duct 35 to effect drying from the surfaceside. The thermal conductive surface of the hot plate 34 is pressed tothe heavily tensioned endless belt 37 to heat the feeding belt 37strongly from its behind by a high pressure steam running at a hightemperature in the hollow inside thereof. The conveyer belt 37 heats themounted cloth 36 by the thermal conductivity directly and effectively.On the inner side of the hot plate, fins 34′ are arranged to collectheat to converge it to the back side of the belt efficiently. The sidewhich is not in contact with the belt is covered with a heat shieldingmember 43 in order to prevent any loss due to heat radiation.

On the surface side, a drying hot air is blown from a supply duct 30 onthe downstream side to supply lower moisture air to the cloth beingdried for the enhancement of its effect. Then, the air containing asufficient amount of moisture running in the direction opposite to theconveying direction of the cloth is drawn into a suction duct 33 by thesuction which is far greater than the drafting to prevent any leakage ofthe evaporated water so as not to form dews on the surroundingmechanical devices. The supply source of the heated air is provided onthe rear side in FIG. 10, and the suction is conducted from the frontside. The difference in pressure between the drafting outlet 38 and thesuction inlet 39 against the cloth is arranged to be even all over thearea in the longitudinal direction. The air drafting and suction unitsare offset to the downstream side from the center of the hot platearranged on the back sides thereof so that the air can be applied to thelocation which is sufficiently heated. Hence, in the first printing unit31, a great quantity of water contained in ink received by the clothincluding the thinning agent is dried intensively.

On the downstream side (upward), the second printing unit 31′ isarranged. The second printing unit is formed with a second carriage 44′of the same structure as the first carriage.

Now, the description will be made of a preferable example of a recordingmethod for the ink jet printing. FIG. 12 is a block diagram illustratingthe printing method. As shown in FIG. 12, a cloth is dried (includingnatural drying) after the ink jet printing process. Then, continuously,the dyestuffs on the clothing fiber are dispersed, and a processing iseffected to fix the dyestuffs to the fiber by reaction. By thisprocessing, it is possible to obtain a sufficient coloring capabilityand durability by the fixation of the dyestuffs.

These processes of the diffusion and reactive fixation can be executedby a conventional method. A steaming method can be executed, forexample. Here, in this case, it may be possible to provide an alkalinetreatment to the cloth in advance before the printing process.

Then, in the post treatment process, the dyestuffs that have not shownany reaction and the substances that have been used in the preparatoryprocess are removed. Lastly, the defect correction, iron finishing, andother finishing adjustment treatments are effected before the completionof the recording.

As recording media that can be used for the recording by an imagerecording apparatus according to the present invention, it is possibleto use cotton, silk, wall papers, papers, OHP film, and others.Particularly, for a recording medium having a low water absorption, suchas cotton, silk, and wall papers, the present invention is preferablysuitable.

Here, in the present specification, the cotton and silk are meant toinclude every woven fabric, non-woven fabric, and other clothsirrespective of the raw materials, the methods for weaving and knitting.

Also, in the present specification, the wall papers include the adhesivematerials for wallpapers which use papers, cloths, or polychloride vinyland other synthetic resin sheets as its raw materials.

Particularly, for the ink jet printing, the cloths are to meet thefollowing requirements:

-   -   (1) Colors should come out on ink in a sufficient density.    -   (2) Dye fixation factor is high for ink.    -   (3) Ink must be dried quickly on the cloth.    -   (4) The generation of irregular ink spread on the cloth is        insignificant.    -   (5) The cloth should have an excellent capability of being fed        in an apparatus.

In order to satisfy these capability requirements, it may be possible togive a preparatory treatment as required to the cloth to be used forprinting. For example, in Japanese Patent Laid-Open Application No.62-53492, the cloths having an ink receptacle layer are disclosed. Also,in Japanese Patent Publication No. 3-46589, there are proposed thecloths which contain reduction preventive agents or alkaline substances.As an example of such preparatory treatment as this, it is also possibleto name a process to allow the cloth to contain a substance selectedfrom an alkaline substance, water soluble polymer, water solublemetallic salt, or urea and thiourea.

As an alkaline substance, there can be named, for example, hydroxidealkali metals such as sodium hydroxide, potassium hydroxide; mono-, di-,and tori-ethanol amine, and other amine; and carbonate or hydrogencarbonate alkali metallic salt such as sodium carbonate, potassiumcarbonate, and sodium hydrogen carbonate. Furthermore, there are organicacid metallic salt such as calcium carbonate, barium carbonate orammonia and ammonia compounds. Also, the sodium trichloroacetic acid andthe like which become an alkaline substance by steaming and hot airtreatment can be used. The alkaline substance which is particularlysuitable for the purpose can be the sodium carbonate and sodium hydrogencarbonate which are used for dye coloring of the reactive dye stuffs.

As water soluble polymer, there can be named starchy substances such ascorn and wheat; cellulose substances such as carboxyl methyl cellulose,methyl cellulose, hydroxy ethel cellulose; polysaccharide such as sodiumalginic acid, gum arabic, locasweet bean gum, tragacanth gum, guar gum,and tamarind seed; protein substances such as gelatin and casein; andnatural water soluble polymer such tannin and lignin.

Also, as synthetic polymer, there can be named, for example, polyvinylalcoholic compounds, polyethylene oxide compounds, acrylic acid watersoluble polymer, maleic anhydride water soluble polymer, and the like.Among them, polysaccharide polymer and cellulose polymer should bepreferable.

As water soluble metallic salt, there can be named the pH4 to 10compounds which produce typical ionic crystals, namely, halogenidecompounds of alkaline metals or alkaline earth metals, for example. As atypical example of these compounds, NaCl, Na₂SO₄, KCl and CH₃COONa andthe like can be named for the alkaline metals, for example. Also, CaCl₂,MgCl₂, and the like can be named for the alkaline earth metals. Saltsuch as Na, K and Ca should particularly be preferable.

In the preparatory process, a method is not necessarily confined inorder to enable the above-mentioned substances and others to becontained in a cloth, but usually, a dipping method, padding method,coating method, spraying method, and others can be used.

Moreover, the printing ink given to the ink let printing cloth merelyadheres to it when printed on the cloth. Therefore, it is preferable toperform a subsequent reactive fixation process (dye fixation process)for the dye stuffs to be fixed on the cloth. A reactive fixation processsuch as this can be a method publicly known in the art. There can benamed a steaming method, HT steaming method, thermofixing method, forexample. Also, alkaline pad steaming method, alkaline blotch steamingmethod, alkaline shock method, alkaline cold fixing method, and the likecan be named when a cloth is used without any alkaline process beinggiven in advance.

Further, the removal of the dye stuffs which have not reacted and thesubstance used in the preparatory process can be performed by cleaningby the publicly known method in the art subsequent to theabove-mentioned reactive fixation process. In this respect, it ispreferable to conduct a conventional fixing treatment at the time ofthis cleaning.

The above-mentioned structure of the ink jet recording apparatus, andthe preparatory and post processes for the cloth are preferablyapplicable to first and second inventive concepts set forth below.

Now, the description will be made of the first inventive concept indetail.

FIG. 1 is a block diagram schematically showing the structure of theprincipal part of a printing apparatus according to the presentembodiment. FIG. 4 is a flowchart showing the control process by acontrol unit 101 of this apparatus.

In FIG. 1, a reference numeral 101 designates a control unit whichperforms the overall control of the printing apparatus. This controlunit comprises a CPU 110 such as a microprocessor; a ROM 111 storing thecontrol program for the CPU 110 as represented in the flowchart shown inFIG. 4 and various data; a RAM 112 used as a work area for the CPU 110to store various data provisionally, and others.

A reference numeral 102 designates a head driver to drive the recordinghead (ink jet head) 301; 103 and 104, motor drivers which drive acarriage motor 105 and a feed motor 106 to be rotated, respectively, inaccordance with instructions from the control unit 101; and 107, asetting switch operated by a user to set the number of multi-scannings.

The user observes the designed patterns to be printed through themonitor screen (not shown) or in the form of its original. If it isdetermined that this image to be printed tends to create conspicuousunevenness and streaks due to the uneven patterns thereof, or it tendsto cause defective ejection from the nozzles of the recording head dueto ink mist resulting from the highly densified portion in the image,the user operates the setting switch 107 to make the number of themulti-scanning to be increased. A case where the multi-scanning is setfor two or three times will be described, for example.

Now, with reference to a flowchart shown in FIG. 4, the description willbe made of the recording process by a printing apparatus according tothe present embodiment.

At first, in step S1, the number of the multi-scannings set by thesetting switch 107 is read, and in step S2, it is determined whethersuch a number is 2 or 3. Here, in this respect, a case where the numberof multi-scannings is 2 or 3 for the sake of convenience, but theprocess can be achieved in the same manner even when the numeral valuesare other than the numbers mentioned as a matter of course.

When the set number is 3, the sequence will proceed to step S3 to dividethe nozzles of the recording head 301 shown in FIG. 3 into three. Whenthe three-time multi-scanning is performed, for example, the twelvenozzles of the ink jet head 301 are divided into three groups of 1-1 to1-4, 1-5 to 1-8, and 1-9 to 1-12. Then, in step S4, using the nozzles1-1 to 1-4, the first, fourth, and seventh images of the image data inthe direction A are recorded at intervals of two data. This process isrepeated until the recording for one scanning portion is terminated.Then, when the recording for one scanning is terminated, the sequencewill proceed to step S6 in which the recording sheet 203 is shifted inthe direction B for an amount of 2d/3, and the carriage is returned tothe home position for a carriage return.

Subsequently, the sequence will proceed to step S7 to record the second,fifth, and eighth images of the image data in the direction A atintervals of two data using the next nozzle block 1-5 to 1-8. At thisjuncture, a recording is performed by the last nozzle block. Then, whenthe scanning for this second scan is terminated, the sequence willproceed to step S9 to shift the recording sheet 203 in the direction Bfor an amount of 2d/3. Thus, after a carriage return, using the nozzles1-9 to 1-12, the third, sixth, and ninth images of the image data in thedirection A are recorded at intervals of two data in steps S10 and S11.At this juncture, too, the recordings are performed by the last and onebefore last nozzle groups.

On the other hand, if, in the step S2, the set number is 2, the sequencewill proceed to step S12 where using the nozzles 1-1 to 1-6, the datathinned by a half of the image data in the direction A are recorded atintervals of one data as shown in FIG. 3. When this one scan recordingis terminated, the sequence will proceed to step S15 to shift therecording sheet in the direction B for an amount of d. Then, after acarriage return, using the nozzles 1-7 to 1-12, the remaining second,fourth, and sixth images of the image data in the direction A arerecorded at intervals of one data in steps S16 and S17. At thisjuncture, the recording is performed by the last block.

In this way, the multi-scannings are performed for the number set by thesetting switch 107 to record the image data.

The number to be set by the setting switch 107 is set to increase thescanning number if there is a need for the recording pattern to acquirea further evenness or there is a higher probability of the disabledejection due to ink mist. Now, since the user can arbitrarily set thenumber of multi-scannings in this way in accordance with the pattern tobe recorded, it is possible to obtain an evenly recorded image of adesirable quality without any disabled ejection irrespective of thepatterns, at the same time enabling the recording without multi-scanningif the object pattern does not require any multi-scanning. As a result,there is no possibility that the recording period of time isunnecessarily prolonged.

Subsequently, the description will be made of a second embodimentaccording to the present invention.

FIG. 5 is a flowchart showing the process of the control unit 101according to the second embodiment.

In FIG. 5, when the image data are inputted in step S21 at first, thesequence will proceed to step S22 to determine the evenness of theinputted image signals and the height of the signal level by a givenmethod. Then, if it is determined that the evenness is high and streaksand unevenness tend to be conspicuous, or the height of the signal levelis high, that is, the disabled ejection tends to take place due to themist resulting from the high density, the set value is so defined thatthe number of the multi-scannings is increased. On the other hand, ifthe evenness of the image data is not so high and the height of thesignal level is not so high, either, the setting is made to reduce thenumber of the multi-scannings. In this way, the optimal number of themulti-scannings is set in accordance with the evenness of the image dataand the height of the signal level.

In this respect, it is possible to adopt a mode where the setting of thenumber of the multi-scannings is performed by determining the optimalnumber of the multi-scannings from the entire image data before printingand thereafter no change will be made, but it may be possible to arrangethe setting in such a manner that an optimal number of themulti-scannings is determined from the image data for one to severalscanning portions and then, such a number may be modified each time.

In performing such a control as this, it is possible to form an even andbeautiful image without any disabled ejection while it becomesunnecessary for the user to set the number of the multi-scannings on thebasis of the image data.

Now, the description will be made of a third embodiment according to thepresent invention. Whereas the process to set the number of themulti-scannings in the foregoing second embodiment is executed by aprogram in accordance with the image data, the number of themulti-scannings is set in the third embodiment by an image determiningunit which is provided for the control unit 101 in a hardware fashion.

FIG. 6 is a block diagram showing the inner structure of the imagedetermining unit.

A reference numeral 301 designates an inputted image data; 501, an edgedetecting circuit to detect the edge portion of the image data 301; 502,the edge signals output from the edge detecting circuit 501; 503, athreshold circuit to receive the edge signals 502 to determine thesignal level thereof; 505, a counter to count the number of the edgesignals 504 which are binary coded by the threshold circuit 503; 507, anadder; 509, a ROM; and 321, a setting value to set the number of themulti-scannings.

The edge detecting circuit 501 is provided with a known differentialfilter circuit, and others to detect the edge portion of the image data301; thus outputting the edge signals 502. The threshold circuit 503outputs 1 when the absolute value of the edge signals 502 is more than agiven value T and outputs 0 when it is T or less to make the edgesignals binary coded. The counter 505 receives the binary coded edgesignals 504 to count the number the data of which is 1, and outputs itstotal sum. Also, the adder 507 adds the image data 301 totally andoutputs its result. The total sum 506 output from the counter 505 andthe added signal 508 by the adder 507 are both inputted into theaddresses of the ROM 509. The ROM 509 outputs a setting value 321 inaccordance with the combination of the respective signals. In otherwords, given the control signal as f, counter signal 506 as C, and addedsignal 508 as D, the following function is obtainable:f=F(C,D)

In the present embodiment, the counter signals 506 and added signals 508are respectively divided into large, medium, and small to determine thesetting values 321 in accordance with the combinations thereof as shownin Table 1.

TABLE 1 Counter signals 506 Added signals 507 Large Medium Small Large 23 4 Medium 2 2 3 Small 1 2 3

In this respect, the threshold values to determine these numbers, large,medium, and small, should be the optimal values that can be obtained inadvance simply by the experiments.

When the counter signal 506 is large, the image data 301 has many edgeportions, and determining that even portions are small, the number ofmulti-scannings is set to be small. Also, when the added signal value508 is small, the recording duty of the recording head is low. Thus,conceivably, there is less danger that the ink ejection defects aregenerated by the mist, and the number of multi-scannings can be set tobe small.

Also, as shown in FIG. 7, it may be possible to set the number ofmulti-scannings in such a manner that the image data recorded on therecording sheet 203 are read by the CCD sensor 350, and the image dataare determined in accordance with the signals thus read in order todecide on the number of the multi-scannings. The CCD sensor 350 shown inFIG. 7 scans following the ink jet head 301 at the same speed as thehead 301 to read the recorded image. The signals read by this sensor 350are inputted into the determining circuit instead of the image data 301in FIG. 6, and the number of the multi-scannings is decided in the samemanner as in the case of the image data 301.

Here, in the foregoing embodiment, the description has been made of acase where one pixel is structured by one dot, but the present inventionis executable also in a case where one pixel is constituted by pluraldots and a multi-valued recording is performed in a tone correspondingto such a number of dots. In such a case, one pixel is constituted bytwo dots X1 and Y1 in FIG. 3, for example, and it is possible toimplement this type of recording by making a ternary image formation. Inthis case, while it is desirable to set the interval between the X1 andY1 dots small, the other structures are the same as the foregoingembodiment.

Here, in the above-mentioned embodiment, the description has been madeof an integrally constructed ink jet head the nozzles of which aredivided for use, but it may be possible to execute the multi-scanningwith separated heads. Also, when the separated heads are used, it may bepossible to position them apart by an integer number of times the widthof the sub-scan feeding in the direction of the sub-scanning.

As described above, according to the present embodiment, it is possibleto obtain beautiful images stably without image unevenness, whitestreaks, or ink ejection defects by making variable the number ofmulti-scannings. The recording speed is not lowered unnecessarily,either.

Hereinafter, the detailed description will be made of a second inventiveconcept.

FIG. 13 is a view showing an example of the image formation in a fourthembodiment according to the present invention. In FIG. 13, a referencenumeral 401 designates an in jet head (hereinafter referred to asrecording head) which is divided into three nozzle portions, X portion411, Y portion 412, and Z portion 413; 402, nozzles of the recordinghead 401; and 403, a recording sheet. Also, a reference numeral 404designates a CCD having four photoelectric conversion elements (readingelements) 10-1 to 10-4 arranged at the same pitches as those of thenozzles 402 of the recording head 401 to read the recorded dots frombehind the recording head 401 by scanning them in the direction A at thesame speed as the recording head 401. In other words, The CCD 404 readsthe image recorded by the X portion 411 and detects whether any disabledink ejection from the nozzles 402 has been generated or not. Thisdetermination of whether any disabled ink ejection exists or not is madeby comparing the image data to be recorded and the reading result of theCCD 404 thus conducted.

FIG. 13 illustrates a state where the nozzles designated by X1 of thenozzles 402 are disabled to eject ink. Consequently, in the portionindicated by X′ in the recording sheet 403, the dots which are supposedto be recorded by the nozzles X1 are missing. This missing of dots isdetected by the pixel 10-1 of the CCD 404 which follows the recordinghead 401 in scanning. Then, after the termination of the recording inthe portion indicated by X′, the recording sheet 403 is shifted in thedirection B. Then, the portion Y′ is recorded by the Y portion 412 ofthe recording head 401. At this juncture, the dots which are notrecorded by the nozzles X1 are recorded by the nozzles Y1 of therecording head 401. In this way, the missing dots due to the defectiveejection of the nozzles are covered.

FIG. 14 is a block diagram schematically showing the structure of aprinter according to the present embodiment. In FIG. 14, a referencenumeral 420 designates a control unit to perform the overall control ofthe apparatus, comprising a CPU 430 such as a microprocessor, a ROM 431storing a control program for the CPU 430 represented by the flowchartsshown in FIG. 15 and FIG. 16 as well as various data, and a RAM 432 usedas the work area for the CPU 430; 421, a head driver to drive therecording head 401 in accordance with the recording data from thecontrol unit 420; and 422 and 423, motor drivers to drive a carriagemotor 424 and a feeding motor 425 to be rotated, respectively.

FIG. 15 and FIG. 16 are flowcharts showing the recording process of theprinting apparatus according to the present embodiment. The controlprogram for the execution of this process is stored in the ROM 431.

This process is started when a one-page portion of recording data isinputted into the printing apparatus to make the recording operationready, for example. Then, at first, in step S41, a carriage scan isstarted to cause the nozzles X1 to X4 of the recording head 401 to ejectink at intervals of three dots in response to the image data inaccordance with the recording data to be recorded by the X portion 411of the recording head 401. Then, the sequence proceeds to step S43 wherethe dots recorded by this X portion 411 on the recording sheet 403 areread by the CCD sensor 404 which is engaged in scanning following thisrecording head 401. Then, if the dots actually recorded and the imagedata to be recorded are not coincident, such a portion is designated as1 and recorded in the complementary data area 433 of the RAM 432 (stepS45). In this respect, this complementary data area 433 is all clearedto zero at the beginning. Thus, in step S46, whether the recordingprocess for one scanning is terminated or not is examined, and if notterminated, the sequence will return to the step S42 to repeat theforegoing process.

When the recording of the one scanning portion is terminated, thesequence will proceed from step S46 to S47 to cause the recording sheet403 to be shifted in the direction B by d. The carriage will return toits home position. Then, in step S48, the logic sum of the recordingdata for the Y portion 412 of the recording head 401 and the data storedin the complementary memory 434 is operated to make such a sum arecording data to perform recording in the Y portion 412. At this time,the contents of the complementary data 434 are again cleared to zero.Then, in step S49, the carriage scan is started. In step S51, thenozzles in the Y portion 412 of the recording head 401 are driven atintervals of three dots to perform recording in accordance with therecording data produced in the step S48. In parallel with this, therecording by the X portion 411 is also performed in the step S51. Thisrecording process by the X portion 411 is the same as the processexecuted in the foregoing steps S42 to S45.

When the one scanning recording is terminated in this way, the sequencewill proceed from step S52 to S53 to conduct the carriage return andshift the recording sheet 403 by d. Then, the recording data to berecorded by the X portion 411, Y portion 412, and Z portion 413 areproduced (step S54). At this juncture, the logic sum of the recordingdata by the Y portion 412 and the contents of the complementary data 434are operated in the same manner as described in the forgoing step S48.Then, the other data are produced by the recording by the use of eachpart of the recording head 401, and when it is terminated, the sequencewill proceed to step S55 to start the carriage scan in the same manneras described earlier. Then, in steps S56, S58, and S60, the recording isperformed using each part of the recording head 401. In this respect,the determination of the presence of the recording data in step S57 andstep S59 is based on the examination of the last termination of therecording data for the X portion 411 and Y portion 412 because therecording of the recording data is terminated only when the recording inthe Z portion 413 is also terminated. Hence, the steps S56 to S61 arerepeated until the one scanning recording is terminated in the step S61,and lastly, in step S62, the foregoing steps S53 to S62 are repeatedlyexecuted until one page recording process is terminated. In thisrespect, the recording process by the X portion 411 in the step S60 isthe same as the process represented in the steps S42 to S45 as in theprocess in the step S51 as described earlier.

As described above, even when the nozzles of defective ink ejectionexist in the X portion 411 of the recording head 401, it is possible torecord the dots corresponding to such nozzle portion by the use of theother nozzles in the subsequent recording process.

Now, with reference to FIG. 17, the description will be made of a fifthembodiment according to the present embodiment.

FIG. 17 is a view illustrating the fifth embodiment, in which the samereference numerals are given to the same structures and parts asdescribed earlier and the descriptions thereof will be omitted. In thisfifth embodiment, a CCD 404 a has photoelectric conversion elements(reading elements) for an eight-pixel portion and is capable ofdetecting eight dots recorded by the X portion 411 and Y portion 412 ofthe recording head 401 at a time. Of this CCD 404 a, the four pixelsdesignated by 11-5 to 11-8 read the image recorded by the X portion 411of the recording head 401 to detect whether any defective ink ejectionexists or not in such portion. FIG. 17 illustrates a case where thenozzle X1 of the recording head 401 is in a state of defective ejection.In this case, the CCD 404 a detects the portions where the dots aremissing, and when the recording is performed next by Y portion 412 ofthe recording head 401, the dots missed by the nozzle X1 for recordingwill be recorded by the nozzle Y1 to complement such dot missing by thenozzle X1. The reading elements represented by 11-1 to 11-4 of the CCD404 a read the dots in the Y′ portion which are recorded by the Yportion 412 of the recording head and compare the image data to berecorded by the X portion 411 and Y portion 412 of the recording head401 and the reading result of dots by the CCD 404 a to determine whetherany nozzles showing defective ejection exist or not. FIG. 17 illustratesa case where the nozzle Y2 of the Y portion 412 is in a state ofdefective ejection. In such a case, the dots missed by the nozzle Y2 ofthe Y portion 412 are recorded using the nozzle Z2 of the Z portion 413of the recording head 401 after the recording sheet 403 has been shiftedin the sub-scanning direction by d; thus performing the recording bycomplementing the missing dot portion in such a manner.

The operation in this case is such that in addition to the inspection onthe recorded dots conducted at the time of recording by the X portion411 of the recording head 401 in the foregoing FIG. 15 and FIG. 16,another process to inspect the recorded dots by the Y portion 412 of therecording head will be conducted, and that the portion where dots aremissing can be complemented in the recording process by the use of the Yportion 412 and Z portion 413 of the recording head 401. Thisimplementation is easy, and here, the description of the flowchart forsuch operation will be omitted.

Subsequently, with reference to FIG. 18, the description will be made ofa sixth embodiment according to the present invention.

FIG. 18 is a view illustrating the sixth embodiment, in which a CCD 404b has twelve reading elements represented by 12-1 to 12-12. Of thesereading elements, the elements designated by 12-1 to 12-4 read the dotsrecorded by the Z′ portion on a recording sheet 403. Then, whether anydot missing is generated or not is detected by comparing the image datato be recorded on this portion and the data thus read; hence producingthe image data to complement this. Then, using a head H which isarranged behind this CCD sensor 404 b, the image data for the portionwhere any dot missing has taken place will be recorded. FIG. 18illustrates a case in which the nozzle Z3 in the Z portion of therecording head 401 is in a state of defective ejection, and this iscomplemented with the recording by the nozzle H3 of the recording headH.

FIG. 19 is a block diagram schematically showing the structure of aprinting apparatus according to this sixth embodiment, in which the samereference numerals are given to the portions corresponding to those inthe foregoing block diagram shown in FIG. 14, and the descriptionsthereof will be omitted. In this printing apparatus, a CCD sensor 404 b,a recording head 401 and another recording head H are mounted on thecarriage, and are integrally shifted by the rotational driving of acarriage motor 424. Also, in a RAM 432 in a control unit 420, there areprovided an X complementary data 435 to store the dot data which are notrecorded in the X′ portion, a Y complementary data 436 to store the datawhich are not recorded in the Y′ portion, and a Z complementary data 437to store the data which are not recorded in the Z′ portion.

The operation of the printing apparatus according to the sixthembodiment is shown in flowcharts shown in FIG. 20 and FIG. 21.Hereinafter, with reference to the flowcharts, the operation of thisprinting apparatus will be described briefly.

The recording process by the X portion of the recording head 401 shownin steps S131 to S137 are the same as the steps S41 to S47 in theforegoing flowchart shown in FIG. 15. Therefore, the description thereofwill be omitted. The sequence will proceed to the next step S138 wherethe logic sum of the data to be recorded in the Y portion of therecording head 401 and the data stored in the X complementary data 435is operated to produce the recording data which will be output to the Yportion of the recording head 401. Then, the sequence will proceed tostep S140 to perform recording by the use of the X portion and Y portionof the recording head 401, and determine whether the dots recorded on arecording sheet 403 and the recording data output to the X portion and Yportion are coincidental or not on the basis of the signals from the CCD404 b (step S141). If found to be incoincidental, the sequence willproceed to step S142 where such incoincidental portion is stored in theX complementary data 435 if it is in the portion X′ on the recordingsheet 403 or stored in the Y complementary data 436 if it is in theportion Y′. Thus, in step S143, when the recordings in the X′ portionand Y′ portion are completed, the sequence will proceed to step S144 toshift the recording sheet 403 in the direction B by d and return thecarriage to its home position.

Then, in the next step S145, the recording data to be recorded by the Zportion and Y portion of the recording head 401 are produced inaccordance with the recording data which should originally be recordedand the contents of the X complementary data 435 and Y complementarydata 436. Thus, in step S146, the carriage scan is started for the nextrecord scanning, and in step S147, the recordings are performed by the Xportion, Y portion and Z portion of the recording head 401. Then, instep S148, the dot data read by the CCD 404 b and the recording data arecompared. If any incoincidental portion is found in the X′ portion ofthe recording sheet 403 on the basis of the result of the comparison,such portion will be stored in the X complementary data 435 or if it isfound in the Y′ portion, such portion will be stored in the Ycomplementary data 436. Then, if such portion is present in the Z′portion, the Z complementary data 437 will be updated. Thus, thesequence will proceed to step S150 where the contents of the Zcomplementary data 437 are output to the recording head H. The finalcomplementary recording will be performed by the recording head Haccordingly.

With a structure such as this, the probability to cover the state of thedisabled ink ejection from the nozzles of the recording head 401 will befurther improved. For example, the dots to be recorded by the X portionof the recording head 401 will never be missed unless the nozzles of theX portion, Y portion, Z portion of the recording head 401 and of therecording head H, which are in the same position, are all disabled toeject ink.

Now, the description will be made of a seventh embodiment according tothe present invention. In this seventh embodiment, if the nozzle X1 ofthe X portion 411 of the recording head 401 is detected by the CCDsensor 404 and found to be in a state of defective ink ejection in theforegoing FIG. 13, for example, it is determined that the probability ishigh for the occurrence of the disabled ejection due to ink mist.

Subsequently, the description will be made of a seventh embodiment. Inthis seventh embodiment, if it is detected by the CCD sensor 404 thatthe nozzle X1 of the X portion 411 of the recording head 401 is in astate of defective ink ejection in the foregoing FIG. 13, for example,the probability is determined to be high for the generation of thedisabled ejections due to ink mist. Thus, the driving condition of therecording head 401 is changed. In other words, according to this seventhembodiment, the driving frequency f for the recording head 401 islowered. If, for example, the recording head 401 has been driven at 2.5kHz so far, this driving frequency is reduced to 2.0 kHz. Accompanyingthis, the scanning speed of the recording head 401 in the direction A isalso reduced.

Then, in the same manner as the foregoing fourth embodiment, the dotsmissed by the nozzle X1 are recorded by the use of the nozzle Y4 whenthe recording is performed by the Y portion 412 of the recording head401 after the recording sheet 403 has been scanned in the sub-scanningdirection (direction B). In this way, any missing dots are complemented.In this respect, the driving frequency and the main scanning speed ofthe recording head 401 at that time remain in the lowered conditions asdescribed above.

The structure of the printing apparatus in this case is the same as theone represented by the blocks shown in FIG. 14, and if the dot data readby the CCD sensor 404 are not coincidental with the data to be recordedin the flowcharts in FIG. 15 and FIG. 16, the revolution of the carriagemotor 424 is lowered in the step S45 to implement the reduction of thedriving frequency of the recording head 401.

Also, in a case represented by FIG. 17, too, if any incoincidental dotsexist in the same manner as the foregoing fifth embodiment, the drivingfrequency of the recording head 401 is lowered. Thus, the revolutionfrequency of the carriage motor 424 is lowered to attain the samearrangement as in the foregoing seventh embodiment.

According to the present embodiment, there is an advantage that nodefective ink ejection will take place in the X portion 411 of therecording head 401, and even if some take place at the time of recordingby the Y portion 412, a proper countermeasure will be taken. Also, ifany defective ink ejection has occurred in the X portion 411 of therecording head 401 and despite the driving frequency of the recordinghead 401 being lowered, the defective ink ejection should occur again inthe Y portion 412 in the following recording process, it is possible tolower the driving frequency of the recording head 401 further and recordthe missing dots by the X portion 411 and Y portion 412 when therecording is performed by the Z portion 413.

FIG. 22 is a view illustrating an eighth embodiment according to thepresent invention. In this eighth embodiment, a CCD 404 b has twelvereading elements 12-1 to 12-12 as in the foregoing FIG. 18. Of thereading elements, those represented by 12-1 to 12-4 read the dotsrecorded on the Z′ portion of the recording sheet 403 and compare themwith the image data to be recorded; thus detecting the presence of theportion where dots are missing. If any missing dots are found, a warningsignal is output. Here, in this case, it may be possible to provide arecording head H to follow as in the case of the foregoing FIG. 18, anda recording process by such recording head H may be conducted in such amanner that the driving frequency of the head H is lowered to reduce thedriving frequency of the carriage motor 424 for the required recording,for example.

As described above, according to the seventh and eighth embodiments, ifany defective ink ejection takes place by the scanned recording, it ispossible to suppress the defective ink ejection due to ink mist byreducing the driving frequency of the recording head.

Now, the description will be made of a ninth embodiment according to thepresent invention. In this ninth embodiment, the ratio between thedensity value of the recorded image data and the density of the recordeddots (the density detected by a CCD 404) is obtained to correct theoutput data to each of the nozzles of the recording head 401 inaccordance with such a ratio.

In a case represented in FIG. 11, it is assumed, for example, that thedensity of the recorded dots read by the CCD sensor 404 is given as D₀,and the recording density estimated from the recording datacorresponding to such density is given as D₁, and the estimatedrecording density is estimated in such a manner that when the value ofthe inputted image data is 80H (H stands for hexadecimal), its recordingdensity is estimated as 0.75 in a case of a printing apparatus where themaximum recording density becomes 1.5 when the maximum value of theimage data is FFH, for example.

Then, when the ratio D₀/D₁ between the density of the actual recordingand the density of the image data is obtained, the control unit 420modifies on the basis of this ratio the image data adjacent to thispixel for the recordings are performed by the Y portion 412 and Zportion 413 of the recording head 401.

FIG. 23 is a block diagram showing the structure of a control circuitfor a printing apparatus according to the ninth embodiment, in which thesame reference numerals are given to the portions common with thoseappearing in the foregoing block diagram shown in FIG. 14.

A reference numeral 440 designates a division unit to calculate theratio D₀/D₁ between the actually recorded density and the density of theimage data; and 441 and 442, γ control units, respectively, to modifythe image data to be output to the Y portion 412 and Z portion 413 ofthe recording head 401 in accordance with the control signals from thecontrol unit 420 a. Now, a case of D₁=1.0 and D₀=1.1 will be considered,for example. Then, the ratio D₀/D₁ becomes 1.1. The recording isperformed at a density which is higher than the estimated density by10%. Here, each of the image data 450, 451, and 452 is the portion ofthe final image data which are divided into three equal portions.Therefore, the recording duty of the recording head 401 for each of theX portion, Y portion, and Z portion is substantially equal. As a result,the temperature rise of the recording head 401 is substantially equal.Hence, if the recording is performed each by the Y portion 412 densityis higher than the estimated density by 10% as in the case of therecording in the X portion 411.

Therefore, when the recording is performed using the Y portion 412, theimage data is multiplied by 1/1.1 (=0.91). Then, the image density to berecorded by the Y portion 412 of the recording head 401 can be equalizedto the estimated density. Only with this, however, the dots alreadyrecorded by the X portion 411 will remain as they are. Consequently,when the recording is performed using the Z portion 413, the image datato be recorded is multiplied by 0.82 (0.9×0.91) to enable the recordeddensity to be 0.9 times the estimated density. The recording will beperformed on the basis of such image data. As a result, the averageddensity of the recorded portions by the X portion 411, Y portion 412,and Z portion 413 will be (1.1+1.0+0.9) /3=1.0; hence making it possibleto obtain the recorded density which is substantially equal to theestimated density.

A process such as this is executed by the control unit 420 a. In otherwords, the control unit 420 a calculates the image data for the Yportion 412 and Z portion 413 as described above and outputs the controlsignals 455 and 456 to the γ control units 441 and 442 of the Y portion412 and Z portion 413.

FIG. 24 is a graph showing the data stored in these γ control units 441and 442. As shown in FIG. 24, the straight line look up table having theinclinations which differ by 0.01 each are stored for 64 lines. Then,the straight lines of the corresponding characteristics are selected inaccordance with the control signals 455 and 456, and the inputted imagedata 451 and 452 are converted for output. Thus, according to theabove-mentioned example, the characteristic corresponding to thestraight line having an inclination of 0.91 is selected by the controlsignal 455 in the γ control unit 441, for example. In the γ control unit442, the characteristic corresponding to the straight line having ainclination of 0.82 is selected.

With a control such as this, the recorded density is always controlledto be coincidental with the estimated density corresponding to the imagedata even if the fluctuation of the recording density is generated bythe temperature rise of the recording head 401 and the like. It is thuspossible to obtain an evenly recorded image as an image finally outputwithout a density fluctuation.

FIG. 25 is a block diagram illustrating a tenth embodiment according tothe present invention, in which the driving voltage for a recording head401 head is controlled by head drivers 421 b and 421 c in accordancewith a density ratio D₀/D₁. In FIG. 25, each of the portions 411 to 413of the recording head 401 is capable of controlling the amount of inkejection in response to the driving voltage. The relationship betweenthis head driving voltage and the density of an image to be recorded isstored in a control unit 420 c. Therefore, the control unit 420 c canoutput the control signals 460 and 461 to drive each of the head drivers421 b and 421 c on the basis of the ratio (D₀/D₁) inputted by a divisionunit 440. Hence, as in the foregoing ninth embodiment, it is possible toadjust the density of the image to be recorded by the recording head401, thereby to suppress the fluctuation of the recorded density.

Also, besides this, it may be possible to arrange the structure so thatthe fluctuation of the recorded density is suppressed by changing thehead driving pulse width of the head drivers 421 b and 421 c by the useof the control signals 460 and 461.

Subsequently, with reference to FIG. 26, the description will be made ofan eleventh embodiment according to the present invention.

FIG. 26 is a cross sectional view of a printing apparatus (recordingapparatus) according to the present embodiment. In this respect, whilethe description will be made of a recording apparatus which is used asan ink jet printer in this eleventh embodiment, the structure of thisrecording apparatus 601 is applicable to the foregoing embodiment.

In FIG. 26, a reference numeral 601 designates the recording apparatusbody; 602, an elongated roll as a recording member (a recording mediumsuch as a recording sheet); 604, a cutter to cut the recording member bya given length; 603 and 605, a pair of feeding rollers, respectively, tofeed the rolled sheet; and 606, a sub-scanning roller to convey andposition the recording member exactly for a given length correspondingto the recording width of a recording head. With the above constituents,a conveying path is structured for the recording member being suppliedfrom the roller 602.

On the other hand, a reference numeral 607 designates a recording sheetcassette to stock the cut sheets of the recording member; 608, a guideunit to guide and feed the recording member wherein the recording memberdrawn and conveyed from the cassette 607 is being fed through the guideunit 608 to meet the conveying path from the foregoing roller 602immediately before the feeding roller 605; 609, a carriage with therecording head mounted thereon, which is supported movably in the depthdirection in FIG. 26 by a pair of main scanning rails 609 a; and 610, aplaten arranged in a position opposite to the carriage 609 to pinch therecording member, which is capable of keeping the recording member flatby preventing it from being raised in recording, at the same time havingmeans of absorption such as an air suction or an electrostaticabsorption board to prevent the recording member to be in contact withthe recording head.

Now, with reference to FIG. 27, the periphery of the recording head willbe described.

The carriage 609 comprises recording heads 609C, 609M, 609Y, and 609Bkfor cyanogen, magenta, yellow, and black, respectively. A referencenumeral 611 designates an ink supply system to supply ink to each of therecording heads 609C, 609M, 609Y, and 609Bk, and is provided with theink cartridges 611C, 611M, 611Y, and 611Bk for cyanogen, magenta,yellow, and black, respectively. Each of these ink cartridges suppliesink to each of the recording heads 609C, 609M, 609Y, and 609Bk by a pumpwhich is not shown through tubes 612C, 612M, 612Y, and 612Bk,respectively; 613, a carriage motor to drive the carriage 609 to scan inthe main scanning direction (in the left and right directions in FIG.27), which drives the carriage 609 to be carried through the pulleys614, 615, and a belt 616 fixed to the aforesaid motor 613; and 617 is amotor to drive the ink supply system 611 to scan in the main scanningdirection (in the left and right directions in FIG. 27) in synchronismwith the carriage 609, which drives the ink supply system 611 to becarried through a driving pulley 618, a pulley 619, and a belt 620 fixedon the aforesaid motor 617.

A reference numeral 622 designates a recording member such as theforegoing rolled sheet or cut sheet to be fed in the upper direction inFIG. 27 by the carrier roller 605 and the sub-scanning roller 606, and623, a capping member positioned to perform a process (hereinafterreferred to as ejection recovery process) to remove the causes to lowerthe image quality. The nozzle surfaces of the recording heads 609C,609M, 609Y, and 609Bk are covered by the aforesaid capping member 623.In this state, the ink ejection by driving the recording heads or inkexhaust by pressure from the recording head nozzles are performed.Further, a high speed airflow is introduced to the surfaces of therecording head nozzles in the capping member 623 to blow off from thenozzle surfaces the remaining ink, dust particles, fluffs, and the likeaccompanying the foregoing ink ejection. The nozzle surfaces are thuscleaned to eliminate the disabled or uneven ejection. A referencenumeral 631 designates a monitor unit arranged on the carriage 609 onthe immediately downstream side of the recording head group in the mainscanning direction (in the right hand direction in FIG. 27) to read therecording state recorded by the recording heads 609C, 609M, 609Y, and609Bk.

Now, with reference to FIG. 28, the structure of the monitor unit 631will be described in detail. In FIG. 28, a reference numeral 633designates a pair of illuminating lamps to illuminate a recording image680; 634, a lens to receive the reflective rays from the recording image680 illuminated by the illuminating lamps 633; and 635, a CCD or anothertype of sensor to convert the recording image 680 photoelectrically inaccordance with the incident light of its reflection through the lens634. The CCD sensor 635 divides one pixel into three approximately. Italso has filters of blue, green and red to monitor the recording image680 as a chromatically resolved image. Also, the number of the readingelements of this CCD sensor 635 should desirably be more than the numberof recording elements (the number of nozzles) of the recording heads609C, 609M, 609Y, and 609Bk, respectively. On the basis of the outputsignals of the sensor 635, whether any disabled ejection exists for anyone of the recording heads 609C, 609M, 609Y, and 609Bk or not, andwhether the recording unevenness is more than a given value or not aredetected. Then, if necessary, the foregoing ejection recovery processwill be executed.

Subsequently, using FIGS. 26 and 27, the description will be made of ausual series of recording sequences. In FIG. 26, when the recordingmember is fed from the roll 602 or cassette 607, such recording memberis detected by a recording member detecting sensor (not shown)positioned immediately before the feeding roller 605. Then, the feedingroller 605 and the sub-scanning roller 606 are driven for a given amountof rotation in the conveying path. These are driven until the leadingend of the recording member reaches the sub-scanning roller 606.

In FIG. 27, when the recording member 622 is fed until its leading endreaches the sub-scanning roller 606, the carriage 609 and ink supplysystem 611 are driven by the carriage motor 613 and motor 617 in themain scanning direction (to the right-hand side in FIG. 27),respectively. At the same time, the recording heads 609C, 609M, 609Y,and 609Bk perform recording in the recording width I as shown in FIG. 27in response to the image signals.

Thus, after the one line recording is terminated, the carriage 609 andink supply system 611 are driven to return to a given position in theleft hand side in FIG. 27, at the same time the recording member 622 isfed by the feeding motor 725 in the sub-scanning direction exactly inaccordance with the recording width I.

After the above-mentioned sequences of the recording and feeding of therecording member are executed for a given cycle, the recording member622 will be discharged outside the apparatus.

Here, the further description of the periphery of the recording heads609C, 609M, 609Y, and 609Bk will be made with reference to FIG. 29.

The carriage 609 roughly comprises a head holder 640 provided with therecording heads for four color portions 609C, 609M, 609Y, and 609Bk(here only a recording head 609C being shown), and a holder carriage 641movable on a pair of main scanning rails 609 a with the head holder 640which is mounted on the carriage. This holder carriage 641 has a pin 642which engages with the head holder 640 in a position (on the right handside in FIG. 29) opposite to the position where the recording head(609C) is mounted, and supports the head holder 640 rotatively with thispin 642 as its pivot. Also, at the other end of this holder carriage641, a spring 643 is tensioned between the head holder 640 and theholder carriage 641. By the tension of this spring 643, the head holder640 is biased toward the holder carriage 641 with the pin 642 as itspivot. Also, the holder carriage 641 is provided with a linear pulsemotor 644 in the vicinity of the spring 643, and the terminal 645 ofthis motor 644 is in contact with the head holder 640. In this way, itis possible to modify the recording position of the recording head(609C) vertically by swinging it with the pin 642 as its pivot againstthe head holder 640 and the spring 643 by controlling the driving of themotor 644. This linear pulse motor 644 remains in a state at rest whenany normal recording is in operation, and is operated when any defectsare generated in the recorded image as described later.

Now, with reference to FIG. 29, the process of the ink supply from theink cartridge 611C to 611Bk will be described. In FIG. 29, a path tosupply ink C from the ink cartridge 611C to the tank 650C is shown. Atthe lower part of the tank 650C, a pump 651C is mounted to perform theejection recovery process by supplying ink C to the recording head 650Cunder pressure. The structure of the liquid path of the ink C is suchthat it extends to the recording head 609C through the supply tube 655Cconnected to the exhaust outlet of the pump 651C and the supplyconnector 652C, and then returns again to the tank 650C further throughan exhaust connector 653C and an exhaust tube 651C. At the time ofrecording, the pump 651C is a rest. The ink C which is being consumedfor recording is self refilled from the tank 650C by the capillaryphenomenon of the recording head 609C through both tubes 655C and 654C.On the other hand, at the time of ejection recovery, the carriage 609returns to the position for the capping member 623 shown by dashed linesin FIG. 27 and the pump 651C is operated in this state. At thisjuncture, ink C is circulated between the tank 650C and the recordinghead 609C through the tubes 655C and 654C, at the same time cleaning offthe dust particles, over viscous ink, and others when exhausted alsofrom the ejection surface of the recording head 609C. Thus, the wasteink exhausted from the recording head is collected into a waste inkbottle which is not shown.

According to the above description, the recording head C for cyanogenand its ink supply path are described, but the same structure is alsoprovided for each color of magenta, yellow, and black.

Subsequently, the description will be made of the operation to detectand correct the defective image recording, which is characteristic ofthis eleventh embodiment.

FIG. 30 is a block diagram showing the operation of the image recordingapparatus according to the eleventh embodiment. The image data 660 whichare transmitted from an image reading apparatus (not shown) such as ascanner or an image input apparatus or other communication means aregiven to a recording unit (recording head) to form the recorded image ona recording sheet in accordance with the image data 660. Also, the imagedata 660 are tentatively stored in a memory 661 simultaneously. On theother hand, a monitor unit 631 reads the recorded image by the recordinghead to form the monitoring image data and transmits them to a correctedimage data forming portion 662. In the corrected image data formingportion 662, the image data 660 stored in the memory 661 and themonitoring data read by the monitor unit 631 are compared by acomparator 720. If the data are the same, it is determined that adesired recording has been obtained. Also, if the recorded image and theimage data stored in the memory 661 are different, it is assumed thatimage defects (disabled ejection) have taken place, and the image datafor this portion are stored in a memory 721. Then, when one-linerecording is terminated and the carriage 609 is on its way to its homeposition, the aforesaid linear pulse motor 644 is driven to modify thevertical position of the recording head thereby to perform a correctionrecording from the different discharging ports of the recording head tocomplement such missing portion in accordance with the corrected imagedata.

If a recording is performed with a defective ejection portion E as shownin FIG. 31, for example, it is determined by the CCD sensor 635 of themonitor unit 631 that the defective ejection is generated by the nthejection outlet of the discharging ports (nozzles of the recording head)numbered one to 256. Also, referring to the driving pulses of thecarriage motor 613 which controls the reciprocation of the carriage 609,the pulse numbers are measured where the pulse number at the time ofstarting the recording is P_(S) and the pulse number at the time ofterminating the recording is P_(E). Thus, for example, with therecognition that the defective ejection takes place between P_(i) toP_(j) among the measured pulse numbers, the position of such a defectiveejection can be specified. In this way, when the carriage 609 is in itsreturning motion, the linear pulse motor 644 is driven to modify therecording position of the recording head in order to execute theintended correction recording for this defective ejection portion E byenabling the discharging port (nozzle) numbered (n+k) to face suchportion in place of the nth nozzle, for example.

Now, with reference to a flowchart shown in FIG. 32, the operation ofthe eleventh embodiment will be described.

At first, in step S161, when one line recording is terminated after therecording heads 609C, 609M, 609Y, and 609Bk have scanned one scanningportion, the recorded image is read by the monitor unit 631 in step S162at the same time. Thus, as described earlier, the corrected image dataare calculated (step S163). Here, if no correction is required (stepS164), the carriage 609 is returned at a high speed (step S166). Duringthis period, the recording sheet 622 is fed by a width corresponding tothe one line thus recorded (step S167). These operations will berepeated until the last line is recorded.

On the other hand, in step S164, if it is determined that a portion tobe corrected (defective ejection) exists, the sequence will proceed tostep S169 where the linear pulse motor 644 is driven to be rotated tomodify the recording position of the recording head without feeding therecording sheet 622; hence enabling a discharging port ((n+K)th nozzle)other than the discharging port which has generated the defectiveejection (nth nozzle) to face the position on the recording sheet wheresuch defective recording has occurred (step S170) as described earlierwith reference to FIG. 31. Then, while the recording head is beingreturned at the same speed as at the time of usual recording, thecorrection recording will be performed (step S171) by causing the(n+k)th nozzle to eject ink on the basis of the corrected image datawhen the recording head reaches such a position where the correction isrequired.

Then, proceeding to step S172, whether such defective ejection is only alocal one (self recovery) or not is determined. If it is found to be alocal one, the sequence will proceed to step S173 where the carried 609is returned to the position opposite to the capping member 623 for theexecution of the ejection recovery process. Thus, in step S174, therecording sheet 622 is fed during this period by one line width in thesub-scanning direction (step S174). Also, the linear pulse motor 644 isdriven to be rotated to cause the recording head to return to the normalposition (step S175) and then, the recording operation for the next linewill be executed.

On the other hand, in the step S172, if it is determined that thedefective ejection is not local one but the discharging port (nozzle) iscompletely clogged, the sequence will proceed to step S176 to determinewhether such defective recording has been caused by the same nozzle ornot and further in step S177 to determine whether it is for the firsttime or not. If it is determined that such is not by the samedischarging port or such is by the same discharging port but for thefirst time, the sequence will proceed to step S173 to execute theoperations to follow thereafter. Otherwise, the sequence will proceed tostep S178 and display a warning to prompt the replacement of recordingheads with the determination that the discharging port is completelyclogged and no recovery is possible even after the recovery process isexecuted once. Then, the sequence will proceed to step S173 to executethe operations to follow without suspending the recording operation.

Therefore, even when a certain discharging port (nozzle) of therecording head is completely clogged, it is possible to perform acorrection recording using some other nozzle without replacing therecording head. As a result, it is possible to conduct an unmannedoperation for a long period of time because it is unnecessary for anoperator to watch the recording condition at all times even in arecording mode where an elongated recording material such as a cloth isused for a long-time recording, for example.

In this respect, according to the eleventh embodiment set forth above,the recording position of a recording head is made variable with respectto a recording sheet by means to vary the recording position by therecording head, but the present invention is not confined thereto. Itwill suffice if only the positions of the recording sheet and recordinghead can be varied interrelatedly. For example, therefore, it may bepossible to make the position of the recording sheet 622 variable withrespect to the recording head by arranging the pair of the feedingrollers 605 and 606 shown in FIG. 27 to be normally and reverselyrotatable.

The present invention produces an excellent effect on an ink jetrecording head and recording apparatus, particularly on those employinga method for utilizing thermal energy to form flying ink droplets forthe recording performance.

Regarding the typical structure and operational principle of such amethod, it is preferable to adopt those which can be implemented usingthe fundamental principle disclosed in the specifications of U.S. Pat.Nos. 4,723,129 and 4,740,796. This method is applicable to the so-calledon-demand type recording system and a continuous type recording system.Particularly, however, it is suitable for the on-demand type because theprinciple is such that at least one driving signal, which provides arapid temperature rise beyond a departure from nucleation boiling pointin response to recording information, is applied to an electrothermaltransducer disposed on a liquid (ink) retaining sheet or liquid passagewhereby to cause the electrothermal transducer to generate thermalenergy to produce film boiling on the thermoactive portion of therecording head; thus effectively leading to the resultant formation of abubble in the recording liquid (ink) one to one for each of the drivingsignals. By the development and contraction of the bubble, the liquid(ink) is ejected through a discharging port to produce at least onedroplet. The driving signal is preferably in the form of pulses becausethe development and contraction of the bubble can be effectuatedinstantaneously, and, therefore, the liquid (ink) is ejected with quickresponse.

The driving signal in the form of pulses is preferably such as disclosedin the specifications of U.S. Pat. Nos. 4,463,359 and 4,345,262. In thisrespect, if the conditions disclosed in the specification of U.S. Pat.No. 4,313,124 regarding the rate of temperature increase of the heatingsurface preferably are adopted, it is possible to perform an excellentrecording.

The structure of the recording head may be as shown in each of theabove-mentioned specifications wherein the structure is arranged tocombine the discharging ports, liquid passages, and electrothermaltransducers as disclosed in the above-mentioned patents (linear typeliquid passage or right angle liquid passage). Besides, it may bepossible to form a structure such as disclosed in the specifications ofU.S. Pat. Nos. 4,558,333 and 4,459,600 wherein the thermally activatedportions are arranged in a curved area.

In addition, it is possible for the present invention to adopt astructure such as disclosed in Japanese Laid-Open ApplicationNo.59-123670 wherein a common slit is used as the discharging ports forplural electrothermal transducers, and also a structure such asdisclosed in Japanese Patent Laid-Open Application No. 59-138461 whereinan opening for absorbing pressure waves of the thermal energy is formedcorresponding to the discharging ports.

Furthermore, as a full line type recording head having a lengthcorresponding to the maximum recording width, it may be possible toarrange a structure either by combining plural recording heads disclosedin the above-mentioned specifications or by a single recording headintegrally constructed to cover such a length.

In addition, the present invention is applicable to a replaceable chiptype recording head which is connected electrically with the mainapparatus and can be supplied with ink when it is mounted in the mainassembly, or to a cartridge type recording head having an integral inkcontainer.

Also, it is preferable to additionally provide recording head recoverymeans and preliminarily auxiliary means which are arranged asconstituents of a recording apparatus according to the presentinvention.

These elements will contribute to making the effectiveness of thepresent invention more stabilized. To name them specifically, suchelements are capping means for the recording head, cleaning means,compression or suction means, preliminary heating means such aselectrothermal transducers or heating elements other than suchtransducing type or the combination of those types of elements, andmeans for effecting a preliminary ejection mode besides the regularejection for recording.

Furthermore, as a recording mode for the recording apparatus, it is notonly possible to arrange a monochromatic mode mainly with black, butalso it may be possible to arrange an apparatus having at least one ofmulti-color mode with different color ink materials and/or a full-colormode using the mixture of the colors irrespective of the recording headswhich are integrally formed as one unit or as a combination of pluralrecording heads.

Now, in the embodiments according to the present invention set forthabove, while the ink has been described as liquid, it may be an inkmaterial which is solidified below the room temperature but liquefied atthe room temperature. Since the ink is controlled within the temperaturenot lower than 30° C. and not higher than 70° C. to stabilize itsviscosity for the provision of the stable ejection in general, the inkmay be such that it can be liquefied when the applicable recordingsignals are given.

In addition, while preventing the temperature rise due to the thermalenergy by the positive use of such energy as an energy consumed forchanging states of the ink from solid to liquid, or using the ink whichwill be solidified when left intact for the purpose of preventing inkevaporation, it may be possible to apply to the present invention theuse of an ink having a nature of being liquefied only by the applicationof thermal energy such as an ink capable of being ejected as ink liquidby enabling itself to be liquefied anyway when the thermal energy isgiven in accordance with recording signals, an ink which will havealready begun solidifying itself by the time it reaches a recordingmedium. For an ink such as this, it may be possible to retain the ink asa liquid or solid material in through holes or recesses formed in aporous sheet as disclosed in Japanese Patent Laid-Open Application No.54-56847 or Japanese Patent Laid-Open Application No. 60-71260 in orderto execute a mode whereby to enable the ink to face the electrothermaltransducers in such a state. For the present invention, the mosteffective method for each of the above-mentioned ink materials is theone which can implement the film boiling method described above.

In addition, as modes of a recording apparatus according to the presentinvention, there are a copying apparatus combined with reader and thelike or those used as an image output terminal integrally or separatelystructured for an information processing apparatus such as a wordprocessor and a computer, and further, those adopting a mode as afacsimile apparatus having transmission and reception functions.

In this respect, the description has been made of a case where one dotconstitutes one pixel in the above-mentioned embodiments, but thepresent invention is not confined thereto. The present invention is ofcourse applicable to multi-valued recording wherein a plurality of dotsconstitute one pixel.

Also, in the above-mentioned embodiments, the nozzles of a recordinghead are all installed integrally therewith, and the description hasbeen made of a case where the recording is performed by drivingdifferent nozzles in accordance with each scanning, but the presentinvention is not confined thereto. It may be possible to performrecording by multi-scanning using the separate recording headsaccordingly. Also, when such separate heads are used, it may be possibleto arrange them in the sub-scanning direction at intervals of a spaceinteger times the width of the sub-scan feeding.

Also, in a case of color image recording, the above-mentionedembodiments should only be implemented for each color.

In this respect, the present invention may be applicable to a systemconsisting of a plurality of pieces of equipment or to a system formedby a single piece of equipment. Also, the present invention isapplicable of course to a case where the operations are executed byproviding a system or an apparatus with a program which enables thepresent invention to be implemented.

As described above, according to these embodiments, even if a disabledejection occurs in one scanning at the time of recording by amulti-scanning, the missing dot is complemented by the following scan;hence making it possible to obtain an image having no image defects atall times.

As set forth above, according to the present invention, there is aneffect that in a recorded image, the defects are significantly reduced.

Also, even if any defects are generated in a recorded image, these areeffectively detected automatically. Also, according to the presentinvention, it is possible to obtain an even image with a smallfluctuation of the density.

The recorded matter applied with additional treatments as mentionedabove is then divided into pieces each having a desired size. Thedivided pieces are treated with a final process, such as sewing,adhesion and solvent welding to obtain final products, for exampleclothes such as one-piece or two piece dresses, ties, swimming suits orpants, bedspreads, covers for sofas, handkerchiefs and curtains. Clothsmade of materials such as cotton or silk and others is treated by, forexample sewing and made into clothes and other commodities as disclosedin MODERN KNITTING AND SEWING MANUAL published by Seni Journal (FiberJournal), SOEN by Bunka Shuppan and many others.

1. An image recording apparatus for recording an image on a recordingmedium by causing a recording head having an arrangement of a pluralityof recording elements to scan the recording medium, said apparatuscomprising: recording means for causing the recording head to scan therecording area of the recording medium plural times for recording,wherein, during scans by said recording means, the recording headpartially overlaps the area previously scanned by the recording head,and the recording area scanned by said recording means is recorded by aplurality of different recording elements; reading means for reading arecorded image recorded on the recording medium by scanning therecording area of the recording medium together with the recording headwhen the recording is executed by said recording means; determiningmeans for discriminating a defectively recorded area by comparing therecorded image read by said reading means and the image information tobe recorded; and complementary recording means for causing complementaryrecording of the defectively recorded area discriminated by saiddetermining means at the time of a subsequent scanning by the recordinghead.
 2. An image recording apparatus according to claim 1, wherein saidreading means detects a density of the recorded image on the recordingmedium, and said determining means discriminates a position having adefective recording density by comparing the density of the recordedimage read by said reading means and the density of the imageinformation to be recorded, and said complementary recording meanscauses complementary recording of the defectively densified areadiscriminated by said determining means by the recording head in thesubsequent scanning.
 3. An image recording apparatus according to claim2, wherein said complementary recording means causes the complementaryrecording by changing a driving voltage of the recording head.
 4. Animage recording apparatus according to claim 2, wherein said determiningmeans discriminates a defectively recorded area and a defectiverecording element, and said complementary recording means causesrecording of the defectively recorded area with a nondefective recordingelement by modifying the position of the recording element when therecording head is in a returning operation.
 5. An image recordingapparatus according to claim 1, wherein the recording head comprises anink jet recording head for performing recording by ejecting ink.
 6. Animage recording apparatus according to claim 1, wherein the recordinghead comprises a recording head utilizing thermal energy for inkejection and is provided with thermal energy transducers to generatethermal energy to be applied to the ink.
 7. An image recording apparatusaccording to claim 1, wherein a change effects printing on the recordingmedium.
 8. An image recording method comprising the steps of: providingan image recording apparatus for recording an image on a recordingmedium by causing a recording head having an arrangement of a pluralityof recording elements to scan the recording medium, the apparatusincluding: recording means for causing the recording head to scan therecording area of the recording medium plural times for recording;wherein, during scans by the recording means, the recording headpartially overlaps the area previously scanned by the recording head,and the recording area scanned by the recording means is recorded by aplurality of different recording elements; reading means for reading arecorded image recorded on the recording medium by scanning therecording area of the recording medium together with the recording headwhen the recording is executed by the recording means; determining meansfor discriminating a defectively recorded area by comparing the recordedimage read by reading means and the image information to be recorded;and complementary recording means for causing complementary recording ofthe defectively recorded area discriminated by the determining means atthe time of a subsequent scanning by the recording head; and recordingan image by applying ink to a recording medium using the image recordingapparatus.
 9. An image recording method according to claim 8, furtherincluding a step of: fixing the ink applied to the recording medium. 10.An image recording method according to claim 9, further including thestep of: performing a cleaning process for the recorded recording mediumsubsequent to said fixing step.
 11. An image recording method accordingto claim 9, including the step of employing a cotton or silk recordingmedium.
 12. An image recording method according to claim 8, furtherincluding a step of: applying a preparatory agent to the recordingmedium before the recording step by the image recording apparatus. 13.An image recording method according to claim 8, wherein the recordinghead comprises an ink jet recording head for performing recording byejecting ink.
 14. An image recording method according to claim 8,wherein the recording head comprises a recording head utilizing thermalenergy for ink ejection and is provided with thermal energy transducersto generate thermal energy to be applied to the ink.
 15. An imagerecording method according to claim 8, including the step of employing acotton or silk recording medium.
 16. An image recording method accordingto claim 15, wherein the recording medium is a wall paper.
 17. An imagerecording method according to claim 8, including the step of obtaining arecorded material.
 18. An image recording method according to claim 17,including the step of processing the recorded material to obtain aprocessed product.
 19. An image recording method according to claim 18,wherein the processed product is prepared by dividing the recordedmaterial into pieces, each piece having a desired size, and adding afinal treatment to the divided pieces.
 20. A method according to claim8, wherein the method effects printing on the recording medium.
 21. Animage recording apparatus for recording an image by applying ink withdifferent recording elements including a first recording element and asecond recording element different from each other with respect to asame scan area on a recording medium while scanning a plurality ofrecording elements relatively with respect to the recording medium,comprising: said second recording element is capable of recording apredetermined area recorded with said first recording element byscanning said plurality of recording elements, by a scan different froma scan for recording with said first recording element, wherein whensaid first recording element is defective, the area recorded with saidfirst recording element by scanning the plurality of recording elementsis recorded with said first recording element and said second recordingelement; reading means for reading a recorded image recorded on therecording medium while being scanned together with said recordingelements; detecting means for detecting a defective recording element bycomparing the recorded image recorded by said image recording apparatusand original image data to be recorded; control means for executingcontrol in such a manner that when said detecting means detects thatsaid first recording element is defective, recording based on image datacorresponding to said first recording element is executed by a recordingscan of said second recording element on the basis of image datasupplied to said second recording element.
 22. An image recordingapparatus according to claim 21, further comprising a third recordingelement for scanning a same scanning area as that of said firstrecording element and said second recording element, wherein, when saidfirst recording element and/or said second recording element is detectedby said detecting means to be defective, said control means executescontrol in such a manner that image data corresponding to said firstrecording element and/or said second recording element, respectively, iscomplementarily recorded by a scan of said third recording elementsubsequent to scans of said first recording element and/or said secondrecording element, respectively.
 23. An image recording apparatusaccording to claim 21, wherein said recording elements discharge inkonto a recording medium by generating a state change in ink.
 24. Animage recording apparatus according to claim 23, wherein the statechange generated in the ink with thermal energy by said recordingelements is generation of a bubble.
 25. An image recording apparatus forrecording an image by applying ink with different recording elementincluding a first recording element and a second recording element withrespect to a same scanning area on a recording medium while scanning aplurality of recording elements relatively with respect to the recordingmedium, comprising: said second recording element is capable ofrecording a predetermined area recorded with said first recordingelement by scanning said plurality of recording elements, by a scandifferent from a scan for recording with said first recording element,wherein when said first recording element is defective, the arearecorded with said first recording element by scanning the plurality ofrecording element is recorded with said first recording element and saidsecond recording element; means for detecting a recording element whichbecomes defective in its recording state among the plurality ofrecording elements, wherein, when recording by said first recordingelement is defective, said second recording element executes recordingon the basis of recording data supplied to said first recording elementby a recording scan on the basis of image data supplied to said secondrecording element.
 26. An image recording method for recording an imageby applying ink with different recording elements including a firstrecording element and a second recording element with respect to a samescanning area on a recording medium while scanning a plurality ofrecording elements relatively with respect to the recording medium, themethod comprising the steps of: discriminating a recording element whichbecomes defective in its recording state from among the recordingelements, wherein when the first recording element is defective, thearea recorded with the recording element by scanning the plurality ofrecording elements is recorded with the first recording element and thesecond recording element; by the second recording element, executingrecording on the basis of image data supplied to the first recordingelement by a recording scan on the basis of image data supplied to thesecond recording element, when recording by the first recording elementis defective.